3D printing materials

3D printing is about to change the world, the news app on my tablet is telling me (as has Brian Micklethwait, for some time). Although the technique has been used for years for making 3D mock-ups, advances in materials mean that it is increasingly used to make the real thing.

But for years, the plastics and the metals that were used were just not robust enough to create a prototype that you could be proud of. They resembled paraffin waxes. They could create the parts, but those parts tended to be flimsy. Because the end product didn’t have structural integrity, the technology was really just for engineers who were creating a product in CAD and needed to see what it looked like in real life.

The revolution took place when companies like 3D Systems started designing radically new materials. (See the article Substance Before Form for more.)

They came up with nanocomposites, different blends of plastics, and different blends of powdered metals. They were then able to create a part that, if you held it in your hand, you’d think it was steel. You can throw it down on the ground against cement, and it looks and acts just like steel.

It’s impressive how the industry has graduated from flimsy, waxy plastics to very, very robust materials that can literally be used as a machine part, rather than just a prototype of a part.

The industry graduated from just being about rapid prototyping—i.e., this is going to be something that’s only an R & D function—to becoming a manufacturing strategy. We can make parts through this method, and the parts can go on the car, and the parts can go on the plane. They can also go in the human body, in the case of dental or medical applications.

Prosthetics is just the sort of area where one would expect 3D printing to take off first, because of the high degree of personalisation needed. Now it seems people are taking it seriously as a mass manufacturing method and investing their money in this direction. I expect this degree of personalisation will spread to other things, where it is merely desired.

July 18th, 2012 |

29 comments to 3D printing materials

Haven’t done the dive yet, but once I figure out the ins and outs from a “complete noob” level, I intend to try a 3dsMax (in which I have skill) to CAD (in which I don’t) conversion to try to replicate some historical artifacts in my possession.

True, they won’t be bloomery iron, and I have no idea if this stuff can hold an edge (in the case of arrowheads I’d use for various destructive tests for my research articles) — but I’d be excited to find out.

As materials advance, this method can be used in more and more parts. That means a company will not need a complete inventory of repair parts. All they’ll need is a 3D printer and a computer filled with CAD designs.

Sooner or later, the cost of printing a part will be less than the cost of maintaining an inventory of it. And when we get to repair parts for antiques and collectibles – the sky’s the limit!

The hype about the new materials is a bit overblown. You can indeed get sintered metals now, among other things, but they’re not remotely as strong as machined or cast parts (let alone heat treated versions of the same).

The resolution of the printers is also not nearly what you can achieve with good machining.

Perry: Yep. Though Next Big Future had an article about two weeks ago (as memory swerves) on a significant improvement already happening.

For my purposes (I’m an experimental archaeologist — the serious sort who gets published but sometimes has to blow three months’ pay for materials to do the research), serious mechanical properties aren’t such a huge deal, but *shape* is critical, and my research field is currently hamstrung-to-death b/c any replicas we can obtain is via the “find a smith who says he’s willing to work to spec, hope he doesn’t flake out over the course of six months, and then once the finished product comes out, see if he actually *did* work to spec” method.

Needless to say, I’ve been watching 3d printing like a hawk since it first emerged, and waiting for the quality/cost factors to let it revolutionize what I do.

There have been some remarkable advances in materials, as said, but they’re still a long way from having direct equivalents for most engineering materials right out of the printer. Most of the metal-like materials require some sort of post-processing to achieve useable strengths and characteristics, and even then they’re nothing-like as strong, stiff or ductile as conventional materials. And, as said, the finish obtainable just sin’t there yet, so secondary machining is also required.

The opportunities for this technology are very significant, but we’re a long way from printing many finished, production parts on-demand. Also overlooked is the fact that 3D printing processes are still glacially slow. Their benefit is that you can make just one part, that’s 90% of the shape of what the final part will be, with zero tooling and low capital investment.

What would really rock my world, and I suspect the worlds of many others similarly situated, would be a 3D carbon-fibre layup printer. Now that would be a catapulting technology.

I agree, it’s not about metals, or mass production, yet. We are another 20 years out for that. Advances in machining can easily outstrip the fastest 3d printers in aluminum, and the result requires no finish besides paint or powdercoat (or nothing for aluminum).

Same mentality: why have replacement parts when your CNC robots can make a replacement in a few seconds. This is today, and very accessable.

Now, if I can get a 3d printer that can layer carbon composites (something a CNC cannot do in seconds) I’m going to find many uses for that!

I’ve also been keeping a “weather eye” on 3D printing, and I had somehow managed to miss the nanocomposites developments.

One things I haven’t seen yet, though – and it’s a gap in the market for someone – is a small and relatively cheap mill by which those 3D printers which use recyclable plastics, can have materials made from those recyclable plastics, recycled – that is, ground back down in-house into powder of a suitable grade for feeding back to the 3D printer.

Having read the preceding article on the 71 year-old who foiled the armed robbery in the most sensible way possible (and good on him), I’m also strangely relieved to see the comment that nanocomposites don’t hold a candle to properly forged steels. The reason for this is that, should the day come when a 3D printer can print all the pieces for assembly into a working firearm, that will be the day that the UK bans 3D printers…

Dave Walker – most of the current crop of 3D printers using plastics are using a filament feedstock. The laser-sintered-powder and -liquid technology has pretty-much been eclipsed by the superior technology of continuous fusion approaches. This allows parts to be made that have 40-60% of the strength of the base material, vs the 10-20% that was realistically available with laser-sintered powders. The filament-fusion approach also allows parts to be built with opposing-grain layers – like plywood – which gives a much stronger and stiffer part than was ever possible with any of the laser-sintered approaches.

I’ve made production tooling, including low-pressure molding and vacuum-form tooling, using filament-fusion machines, that has lasted for multiple thousands of parts. That may be where the next big step for 3D printing lies – not to make the parts, but to make the tools to make the parts.

Besides, the laser-sintered-powder and -liquid machines are/were an operational nightmare that required a lot of babying. The current crop of filament-fusion machines literally are fire-and-forget.

Even so, the scope for recycling plastics for use in 3D printing is pretty limited – these are not your run-of-the-mill commodity plastic materials, where you can throw anything similar in the regrind hopper and get a result. These materials are carefully engineered for low melt temeperatures, high surface tension and fast freeze. I don’t think there’s much future in trying to use recycled materials.

As an inventor, this should worry me- BUT I note that these things should still include the warning ‘Some assembly will be required’. Can they actually 3Dprint a moveable nut on a bolt of 3mm diameter? (I am building something small and I use bolts like that for my prototypes.)
When we get to the stage where we will be able to 3dprint a working microwave oven- then the end of the factory floor will be here- and us inventors might be fighting for our patents! (Or maybe not- people won’t want to keep patterns around if they don’t need to, so a private memory bank might keep complex designs on tap, and broadcast them when a customer buys a copy- so iinventors would licence these pattern-stores, like libraries now, and get royalties from copies sent.)

What I’m waiting for is food-safe ceramic printing with fine resolution. IIUC, most of the materials used in 3D printing have the unfortunate property of being poisonous. And the tactic of printing a hi-rez ceramic powder shape, and then glazing it with a safe glaze, necessarily diminishes the surface detail significantly.

Regarding the recycling, I saw someone post on Thingiverse a work in progress design extruder to recycle failed prints back into filament that the printer can use. A good idea as there seems to be quite a bit of trial and error in the printing, however I’m not sure how the energy (& time) cost to reprocess the scraps vs the cost of buying fresh material will compare.

As for IP concerns, they’re already causing problems. Someone put up a design for an ‘impossible triangle’ last year and a DMCA takedown was issued and honoured although it was later rescinded.

I’m sure the lawyers will be only too happy to mine this new seam of IP rights, once 3D printers become more popular. There are already a number of sites selling printed items or even making custom items to order with quite a nice markup. I think this will only increase when you consider the cost of entry is constantly falling and you are getting others working on the other end of the puzzle – scanning.

Although this serves no practical purpose, that we can now make something like this with an out-of-the-box non-professional appliance is impressive. (No affiliation btw, I’m looking at getting a 3D printer, & I’m hankering after a Leapfrog)

Although this serves no practical purpose, that we can now make something like this with an out-of-the-box non-professional appliance is impressive. (No affiliation btw, I’m looking at getting a 3D printer, & I’m hankering after a Leapfrog)

Russ in Texas – I’m sure you understand that, if you give machines like this to a bunch of engineers, they’re going to end up using them for all sorts of things. So we do have a fair amount of experience in what you might call off-label applications.

For any of the metal technologies – I would suggest that you wait a bit. I don’t see them as yet being ready for what you describe without a lot of post-processing.

If you are looking for 99%-realistic replicas of historical metal artefacts, I think I would suggest that you see if you can find a good powder-metal processor, who will almost-certainly be in China these days. These folks have some technologies for making short-run parts that are almost-as-good-as-machined for surprisingly-little money.

You can also exploit some of the really-snappy scanning techniques now coming into wide use, and simply export a 3D scan to a 5-axis milling machine, which will make a perfect replica.

For plastic materials, for the high-end amateur or the low-end professional, I would recommend the U-Print desk-top 3D printer. This machine is made by Stratasys, which makes a lot of much-larger and higher-end machines, but it is sold under several licensed named, including one version by HP. This is a full-function filament-fusion machine that uses the latest and best soluble-support technology. I believe the latest models can be bought for less than U$14K. The range of available materials is limited at present but expect it to expand, just as it has for their higher-end ‘Dimension’ machines. This is a kick-*ss little machine that will take files directly from your better CAD systems and handle all of the processing in a simple, user-friendly GUI format. The filament material is a little spendy, but I guess that’s their business model – razors and blades.

With one of these and a little imagination, it’s just stunning what you can make. The ‘party piece’ for this machine is an 8″ Crescent wrench, grown in a single build (no assembly), that works. I have built complete, working inkjet printer mechanisms on this very machine. I think it’s the most-advanced and most-accessible machine on the market right now. But wait 5 minutes . . . .

I was going to reply to Russ, but llamas seems to have covered it pretty well. One additional thought, though: it may be that 3D scanning technology reaches your cost and resolution targets before 3D printing does. Even if you can’t yet produce physical replicas of sufficient quality, if you have an inventory of items you want to one day replicate you may be able to start on scanning them and storing the data.

I don’t know anything about your field, but it’s possible that the scanned data might be useful to you in other ways, too. Perhaps you can categorize items by dimensions or physical features? Engineering experience has been that 3D models revolutionize the design process by becoming a database of all engineering information about the component, and the set of all models becomes a meta database for the entire product line. It’s possible that the scanned models may be more valuable than the replicas.

Down the road, if it were done in an institution with a large artifact base, Tedd, I think you’re dead on the money. In my case, as an experimental archaeologist, I take the replicas and do ugly tests with them to try to answer historical questions (think Mythbusters, but academically rigorous rather than built-for-entertainment).

You folks, if you’re interested here and aren’t a pro, need to check out tinkerCAD.

I saw a link to it and tried it out on a lark. WAY toned-down compared to 3dsMax or Blender (what I have experience with), let alone real CAD programs like LLama and folks use. But by that token, very fast to use — fast enough that I did a half-dozen models in roughout, which I then took to 3ds for polishing prior to kicking out models.

Currently have “options” for the 3dspainting, and a guy with a 5-axis waterjet who’ll look into cutting costs on that front, too.

I’ll keep you updated — while 3d printing may be a huuuuuge thing, I suspect that tools putting 3d modelling within reach of Clueless Liberal Arts Grads like myself may be the real enabling factor.

Because that one requires money, you have to build it yourself, and it comes with a notable learning curve that’s different from the skillset I have (lots of issues on the help forum). While I think that’s inevitably the best way to go, I keep a LOT of fires burning at any one time, and can’t just drop everything to focus on a single thing for a week.

Other folks might get a lot more mileage out of the David scanner, but for my personal ROI, I need off-the-shelf solutions that fit a *very* modest salary.

I’ve been constructing a (full sized) model of a 12 pounder naval gun using 3d printing for the more complicated parts of the breech. The level of detail is very good, far better than I would have been able to construct by hand methods, although some of the round sections are facetted as an artifact of the 3d software used to construct the digital model. A little sanding soon puts that right since I’m getting them printed in plastic to keep the costs down. I’ve been getting my prints through a french firm called Sculpeteo, has anybody used any other firms that they can recomend so that I can compare prices?

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